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  • A new study looks at how stroke and cognitive impairment are related.
  • The research found as many as 1 in 3 people who have a stroke develop dementia within 5 years.
  • Cognitive impairment is common among stroke survivors, and often under-diagnosed, according to researchers.

Over half of people who survive a stroke go on to develop cognitive impairment, ranging from mild memory and attention issues to dementia, according to new research from the American Heart Association.

The analysis, published Monday in Stroke, the peer-reviewed scientific journal of the American Stroke Association, found that as many as 1 in 3 people who have a stroke get dementia within five years. 

Most people never fully regain pre-stroke cognitive function

The researchers reviewed an assortment of clinical trials, prospective and retrospective cohort studies, case-control studies, clinical guidance, and editorial reviews on the prevalence, diagnosis, and management of post-stroke cognitive impairment (PSCI). 

They found that up to 20% of stroke survivors with mild cognitive impairment recover fully within a year, however, most people never regain their pre-stroke cognitive function. 

Because cognitive impairment is common among stroke survivors, and often under-diagnosed, the researchers hope their findings will highlight the importance of regular screenings.

Dr. Liron Sinvani,, an assistant professor at the Institute of Health System Science at the Feinstein Institutes for Medical Research in Manhasset, New York, says early screening and ongoing monitoring are crucial as cognitive impairment after stroke tends to progress over time.

“Early cognitive therapy and addressing stroke risk factors may be key in improving outcomes,” Sinvani told Healthline.

Most people deal with cognitive impairment post-stroke

According to the report, cognitive impairment is most common in the first year following a stroke and affects approximately 60% of stroke patients. 

Some people, particularly those with a history of stroke, develop late-onset cognitive decline that occurs months after their stroke. 

“Strokes contribute to cognitive issues because they cause a lack of blood flow and oxygen to the brain, causing neuronal injury and even death. This can directly lead to cognitive impairment and dementia,” says Sinvani.

Pre-stroke cognitive impairment, older age, hypertension, and diabetes can contribute to future cognitive decline, too, the study shows. 

The report also found that Black people who experience stroke are more likely to develop cognitive decline and have a greater risk of dementia.

The severity of cognitive impairment, which can range from mild impairment to dementia, varies from person to person and is influenced by stroke severity and whether they’ve previously had any strokes. 

Despite the fact that many stroke patients develop cognitive impairment, it continues to be under-recognized and under-diagnosed, the report shows.

“Cognitive impairment may be underreported in stroke survivors because the person and family may think that memory loss is a normal phenomenon after stroke or may think the symptoms are part of the stroke,” Sinvani says. 

Early diagnosis leads to earlier treatment and stronger recovery

It’s crucial for stroke survivors to undergo routine screening for cognitive impairment, however, there is currently no gold standard for cognitive screening in stroke survivors, the study states.

Brief screening tests — like the Mini-Mental State Examination and the Montreal Cognitive Assessment — are commonly used to identify memory, thinking, and attention issues in stroke patients. 

By conducting regular screenings, healthcare providers can evaluate each person’s cognitive function and risk factors for future decline.

This can help providers gauge whether people are able to return to work, for example, or continue driving, says Dr. Adi Iyer, a neurosurgeon and neurointerventional surgeon, of Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, CA.

The findings also illustrate the need for guided cognitive therapy in order to give patients the best chance of meaningful recovery, says Iyer. 

Some people who do cognitive rehabilitation see improvements in attention, memory, and executive functioning. 

“Cognitive therapy should be a necessary adjunct to physical therapy during recovery. Like physical exercise, mental exercise is essential for patients to make a complete recovery,” he said.

Cognitive impairment can improve with certain interventions like physical activity and secondary stroke prevention strategies.

The progressive nature of PSCI “can be slowed or even stopped by addressing risk factors of stroke such as blood pressure and diabetic control, weight loss, and exercise,” says Sinvani.

The bottom line:

Over half of people who survive a stroke go on to develop cognitive impairment, ranging from mild memory and attention issues to dementia. Though some stroke survivors with cognitive impairment recover fully within a year, most people never regain their pre-stroke cognitive function. Early screening and monitoring can help identify people experiencing cognitive decline after stroke so the progression can be slowed and, in some cases, stopped.

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